import string
import re
str_c=input("请输入字符串：")
str_letter=string.ascii_letters
dict_letter={}
for letter in str_letter:
    dict_letter[letter]=[]
for i in str_c:
    dict_letter[i].append(i)
for count in str_letter:
    if len(dict_letter[count])!=0:
        print(count,len(dict_letter[count]))
for i in str_c:
    str_letter = re.sub(i,'',str_letter)
print(list(str_letter))

